In Risen 2 you work for the inquisition but need to secrectly join pirates to find the source of the titans. Engage in quests, loot, train, barter and obliterate all kinds of seafearing creatures. Explore the beautiful world of Risen and make your own decisions to solve any quest to unlock new skills and paths.

Conclusion:
Risen 2 Dark Waters ran really well on my GeForce 550 Ti. I didn't experience any bugs or crashing. Animation is really smooth and the world is very alive with vegetation moving, water, creatures and day/night cycle. Everything performed great.

Did you ended up playing the whole game under this setup or tested it more? Now that GOG has it on sale I'm really curious on how did this went on the long run, on the video you posted the game seems to go a bit slow specially at some parts were the camera moves but it might be just the video.

I played at least 5 hours or more. It has a slow pace because of all the dialog. Most of my video's get a lower frame rate because I'm playing the game and recording. I had no frame rate issues playing the game alone.
Its your call because a small handful of game play fine and then crash at a certain point. Check on WineHQ's for any reports of people not able to play the entire game.